Which part of the cell cycle is the longest?

Interphase is indeed the longest part of the cell cycle, comprising the majority of the cycle's duration. During interphase, the cell undergoes growth and prepares for division, which includes three specific phases: G1 phase (cell growth), S phase (DNA synthesis and replication), and G2 phase (further preparation for mitosis).

The cell spends significant time in interphase, where it carries out its normal functions while also preparing for cell division. In contrast, the M phase, which consists of mitosis and cytokinesis, is relatively short, typically taking only a few hours. The G1 and G2 phases can vary in length but are generally shorter than interphase as a whole. The S phase is important for DNA replication, but it also constitutes only a portion of interphase, making it shorter than interphase.

Overall, the primary reason interphase stands out as the longest phase is due to its critical roles in cell growth, maintenance, and preparation for division, allowing the cell to ensure that it is ready to replicate successfully before entering the much shorter M phase.